Drafting-square



.(No Model.) l

W. WARD.

DRAPTING SQUARE'.

No. 368,797` Patented Aug. 23, 188'?u iv. Fig-av M M4 o RVUCOY wwe/um Nvu/5 N. PETERS, Phulcrmlmgmplmr UNITED STATES PATENT OFFICE.

YVILLIAM WARD, OF COUNCIL BLUFFS, IOVA.

DRAFTING-SQUARE.

SPECIFICATION forming part of Letters Patent No. 368,797, dated August 23, 1887.

Application filed November 26, 1886. Serial No. 219,939.

To all whom, it may concern:

Be it known that I, WILLIAM WARD, a citizen of the United States, residing at Council Bluffs, in the county ot' Pottawattaniie and State of Iowa, have invented a new and useful Drawing-Board and Square, of which the fol-v lowing is a specification.

My invention relates to improvements in drawing-boards and squares to which adjustable scales of linear measurement are attached, iirst, for the purpose of locating points upon drawings; second, for locating points while copying drawings; third, for locatingponts when reducing or enlarging drawings. I attain these objects by the mechanism illustrated in the accompanying drawings, in which--` Figure l is a view of the drawing-board with paper, square, and scales; Fig. 2, au enlarged section perpendicular to the surface of the board through the line a b 0n Fig. l; Fig. 3, an enlarged section through the blade of the square on the line c d, Fig. l; Fig. 4, a view or" a drawing-board and square with scales for copying; Fig. 5, a view ofthe draw ing-board and square with scales for reducing a drawing, as M, Fig. l.

Similar letters refer to similar parts in Figs. l, 2, and 3.

The channel-bar C isv let into the drawingboard B iiush with its surface and fastened. The channel-bar C and the scale D correspond in section, so that the scale D can be readily adjusted by sliding it endwise. The channelbar E is secured to the blade G of the square S, forming, with G, a groove in which the scale F will slide easily.

I attain the Irst object by drawing lines of reference, as R R and T T, Fig. l, perpendicular toweach other and parallel with the scales D and F. Adj ust the 07s of the scales to these lines of reference and iind. a point, as Z, situate in this instance six units of the scale from R R and ten from T T, by placing the upper edge ofthe square-blade at 6 on the scale D and marking the point at 10 at the edge of the scale F.

The manner of finding a point now in use is by marking its distance from one line of reference with dividers or a scale, drawing an auxiliary line through the mark, and nding (No model.)

the position of the point upon this auxiliary line by a separate measurement of its distance from the other line of reference.

I attain the second object by two scales set parallel with each other, as illustrated in Fig. 4, to be moved perpendicular to their length. I-I in this gure is the surface of a drawingboard; I, a square, the blade of which carries the scale K. J is an additional scale, secured to the stock ot the square I parallel to the scale K. I copy a drawing, as A, Fig. 4, by placing the upper edge of the scale J against .a line parallel with the scale, observing the distance of its ends from the line of reference L L, and drawing a line between corresponding points against the lower scale, K, while the combination is in the same position. Sinvgle points at the end of oblique lines or in curves are found by adjusting the edge ofthe scale J to them, noting their distance from the 'line of reference L L, and marking them against corresponding iigures at the edge of the lower scale, K, in a similar manner.

The method of copying a drawing now in use is to draw auxiliary lines through pointsl in the original, extending far enough to pass through the copy. Then locate thepoints upon these auxiliary lines by separate measurements.

I attain the third object by making the copy with scales ofa different denomination to those placed upon the original. Let M, Fig. l, be the original drawing to be copied, andN, Fig. 5, adrawing-board upon which (in this instance) a copy half lineal size is to be made; O, a scale upon the board N, P, a square with a scale, Q, upon it, all corresponding to similar parts on Fig. l, except as to size. I adjust the scales O and Q, Fig. 5, to the lines of reference U U and V V, place the square S, Fig. 1, against a line, and observe the figure indicating its height upon the scale D., I then place the square P against the corresponding ligure upon the scale O, Fig. 5. Next observe the position of the points to be transferred from Fig. 1` and mark them against corresponding gures upon the scale Q, Fig. 5.

The present manner of reducing or enlarging drawings is by making separate measure ments for each point with a scale or dividers.

ICO

This mechanism does not come into compe- An adjustable scale, in combination with a tition with the pantograph, because the pandraftingfsquare blade adapted to slide in a tograph cannot be used conveniently upon groove in a fixed channel-bar for the purpose i 5 drawings composed of straight lines and geoof locating points upon drawings, substan- 5 metrical curves, and not at all Wherepoints are tially as described.

to be marked down from measurements of an object. WILLIAM WARD.

I do not claim the use lof adjustable scales upon drawing-boards, knowing that they have Witnesses: Io been patented already. JOSEPH LYMAN,

What I claim as my invention, and desire HoMER H. FIELD. to secure by Letters Patent, is 

